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  7. Sensor Main Unit 15A/20A Type

Clamp-on Flow SensorFD-Q series

Sensor Main Unit 15A/20A Type



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Supported pipe diameter

1/2" (15 A), ø18 to ø23 (mm)
3/4" (20 A), ø23 to ø28 (mm)

Supported pipe materials

Metal pipe/Resin pipe*1

Supported fluids

Various liquid [i.e. water (including DI), oils, chemicals, etc.]*1

Supported fluid temperature

0 to 85°C 32 to 185°F (No freezing on the pipe surface)*2

Maximum rated flow

1/2" (15 A): 60 L/min, 15.9 G/min
3/4" (20 A): 100 L/min, 26.4 G/min

Zero cut flow rate

2.5 L/min (Default)*3

Display method

Status indicator, output indicator, dual row display with 4-digit, 7 segment LED, stability level indicator

Display update cycle

Approx. 3 Hz

Display resolution

0.1/ 1 (Default : 0.1) (L/min)

Response time

0.5 s / 1.0 s / 2.5 s / 5 s / 10 s / 30 s / 60 s

Protection circuit

Power supply reverse connection protection, power supply surge protection,
each output short-circuit protection, each output surge protection


0.5 s : ±2.0%, 1 s:±1.5%, 2.5 s : ±1.0%, 5 s : ±0.5%, 10 s : ±0.35%, 30 s : ±0.2%, 60 s : ±0.15% (/F.S.*4(Specific to selected response time))



Integrated flow unit display

0.1/ 1/ 10/ 100/ 1000 (Default : 1) (L)

Integrated flow data storage cycle

Save to memory every 10 seconds

Memory backup

EEPROM (Data storage length: 10 years or longer, Data read/write frequency: 1 million times or more)

Power I/O connector

M12 4-pin connector

Input/Output (Selectable)

Output (ch.1/ch.2)

Control output/ Pulse output/ Error output (Selectable, Default : ch.1 control output/ ch.2 not used),
NPN/PNP setting switchable,open collector output 30 V or less, max. 100 mA/ch., residual voltage 2.5 V or less*5

Analog output (ch.1/ch.2)

4 to 20 mA / 0 to 20 mA (Selectable, Default: not used), load resistance 500 Ω or less*5

External input (ch.2)

Integrated flow reset input/ Flow rate zero input/ Origin adjustment input (Selectable, Default: not used),
short-circuit current 1.5 mA or less, input time 20 ms or more*5

Power supply

Power voltage

20 to 30 VDC , ripple (P-P) 10% max, Class2/LPS

Current consumption

100 mA or less (Load current excluded)*6

Environmental resistance

Enclosure rating

IP65/IP67 (IEC60529)

Ambient temperature

-10 to +60 °C 14 to 140 °F (No freezing)

Relative humidity

35 to 85 % RH (No condensation)

Vibration resistance

10 to 55 Hz, Double amplitude 1.5 mm 0.06", 2 hours in each of the X, Y, and Z directions

Shock resistance

100 m/s2, 16 ms pulse, 1,000 times in each of the X, Y, and Z directions


Sensor main unit


Sensor surface


Mounting bracket



Approx. 400 g (including mounting bracket)

*1 Liquid must allow for the passage of an ultrasonic pulse, as well as not contain large air pockets or excessive bubbles. Detection may be unstable on certain non-standard pipes (i.e. lined pipes)
*2 Contact KEYENCE when the temperature of the pipe is greater than 85°C 185°F
*3 The zero cut flow rate can be changed in the settings. When using the unit with a low flow rate range, perform an origin adjustment when the fluid is not moving if you change the zero cut flow rate.
*4 This specification is valid when the flow velocity distribution is stable. This value does not take into account the effects of pulsation or fluctuations in flow velocity distribution due to facility factors. Convert the F.S. (full scale) listed in the table according to the rated flow range.
*5 IO-Link: Compatible with Specification v1.1 / COM2 (38.4 kbps) The setting file can be downloaded from the KEYENCE website. If using the unit in the environment where downloading the file is not possible via internet, contact your nearest KEYENCE office. IO-Link is either registered trademarks or trademarks of PROFIBUS Nutzerorganisation e.V. (PNO)
*6 When including the loads, please add 200 mA to this value.

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Process Controls / Process Sensors